WP1130

Degrasyn suppresses the growth of K562 heterotransplanted tumors as well as both wild-type Bcr/Abl and T315I mutant Bcr/Abl-expressing BaF/3 cells transplanted into nude mice. To assess the possible therapeutic activity of Degrasyn against CML, nude mice received a subcutaneous transplant with K562 cells and are treated with 30 mg/kg Degrasyn every other day for 9 days after palpable tumor formation (10 days). This dose and schedule are well tolerated and effective in other tumor models. Antitumor activity is compared with that after daily Imatinib mesylate treatment (50 mg/kg). Nineteen days after tumor inoculation, tumors in the control group reached maximum allowable dimension, and the effect of therapy is assessed. Degrasyn treatment suppresses K562 tumor growth to an extent comparable to that observed in imatinib mesylate-treated animals, suggesting that Degrasyn is active in reducing the growth of established K562 tumors^[1].